Internal-combustion engine



April .1929, L. 0. FRENCH INTERNAL COMBUSTION iENGINE I Filed July 22,1927 INVENTOR. (5W1 am Patented Apr. 9, 1929..

UNHTE srrss icense LOUIS 0. FRENCH, F MILWAUKEE, WISCONSIN.

INTERNAL-COMBUSTION ENGINE.-

Application filed July 22,

The invention relates to internal combustion engines ,and moreparticularly to solid fuel injection type engines.

The general object of the invention is to provide'a combustion chamberfor efficiently mixing and distributing the fuel and fuel mixture tobring about good combustion. More particularly, the invention consistsin providing a cavity between apart of the piston and head into whichthe whole or a part of the'fuel is introduced during the compres. sionstroke and which cavity is then'in restrictedcommunication with theremainderof the combustion. chamber into which the '15 fuel issuesthrough an annular passage of gradually increaslng capacity in thedirection of flow toward the walls of the cylinder. This cavity ispreferably formed in the piston and the head is provided with aprojection which enters said cavity near the end of the compressionstroke, and the walls of the piston and head are formedv to give gooddistribution of the gases issuing from said cavity which acts as avaporizer without the dis advantages of permanent restriction ordifiiculty of scavenging and permitting of efficient operation at highspeeds.

A further object of this invention is to provide an improved method ofoperating high speed internal combustion engines of the general typeabove described.

, The invention further consists in the sev era-l features hereinafterset forth and more particularlydefined by claims at the conclusionhereof.

In the drawings, Fig, '1 is a detail vertical sectional view through anengine embodying the invention having valves in the head;' I

Fig. 2 is a similar view, more particularly of a port-scavenging twocycle engine;

Fig. 3 is a view similar to Fig. 2, showing certain. modifications.

Referring to Fig. 1, the numeral 4 designates the cylinder, 5 the pistonworking there in, 6 the cylinder head, 7 the inlet valve, 8 the exhaustvalve and 9 a fuel injector of any suitable construction. The injector 9is-arranged centrally in the head in line with a cavity 10 in the top ofthe piston and near the end of the upstroke 'a projection lion said headenters said cavity and forms a restricted passage 12 between it and themouth of the cavity. To create a turbulent effect the inlet valve 7 mayhave a semi-cylinder deflector 13,

1927. Serial No. 207,771.

of known construction, to direct the air tangentially of the cylinderwall on its entrance. Beyond the passage 12 the head and piston arecurved to provide a flaring passage 14 of gradually increasing capacityin the direction of flow toward the outer space 15.

Referring to Fig. 2. the numeral 16 designates the cylinder, 17 thepiston working therein, 18 the cylinder head and 19 the fuel injector.The injector 19 is arranged centrally in the head in line with a cavity20 in the top of the piston and near the end of the up stroke aprojection 21 on said head enters said cavity and formsa restrictedpassage 22 between it and the mouth of the cavity.- Be-. yond thepassage 22 thehead an'd piston are shaped to provide a flaring passage23 of gradually increasing capacity in the direction of flow toward theouter space 24.

The restriction may be formed by the nozzle itself or a part of the head.castingor a part secured thereto and by the term projection on the headI mean to include any of these constructions, though where theprojection is formed independent of the nozzle the nozzle may terminateabove the, lower end of said projection, as shown in Fig. 2.

In each of the constructions above described the parts preferably comeinto restricted relationship when the piston is within about forty-fivedegrees or less from upper dead center, depending upon the speed of theengine. the greater angle being used for high speed engines so that someor "all of the fuel will be 'dischargedby the nozzle into said cavity,though for high speed engines it is preferred to use'a nozzle with awide spreading jet or jets-so that some of the fuel strikes the curvedmouth of the cavity and does not enter thecavity itself. The fuelinjection is started-slightly before or during the time the parts moveinto restricted eomnmnication and is continued during the remainder ofthe compression stroke and as the piston starts down. the so-calledmixed combustion cycle (partly constant pressure and partly constantvolume) bcingpreferred. As the atomized fuel encounters the heated airin the cavity it is vaporized or gasilied and due to the restrictionbuilds up a greater pressure than in the outer space 15 or 24, with theresult that this gaseous mixture is expelled through the flaring passage14 017 23 into said outer space as the piston starts on its down stroketo mix space 38 may be provided between the outer with the air in saidouter space. Thus the pressure of combustion in a temporarilyrestri'cted portion of the main combustion chamber is used to expel thefuel charge into the ren'iainder of said chamber through a passage ofgradually increasing capacity in the direction of flow and since duringthe restricted relation of the parts either the air entering the chamberor the gases issuing therefrom flows throughthe passage 14 or 23' atconsiderable velocity any fuel temporarily deposited on the piston atthemouth of the cavity will be carried along in the air or gas stream. YThe construction shown in Fig.3 is generally similar to that of Fig. 2except that I have here provided a restriction beyond the flaringpassage-so that the pressure is in creased after the gases make the turntoward the outer space. In this figure the numeral 25 designates thecylinder, 26 the pistonworking therein, fuel injector.

The injector 28 isarranged centrally in the head in line with a cavity29 in the top of the piston and near the end of the up stroke aprojection 30 on said head enters said cavity and'forms a restrictedpassage 31 between it and the mouth of the cavity. Beyond therestriction the head and piston are shaped to provide a flaring passage32, a restricted passage 33, and an outer space 34, the passage 33 beingmost restricted at the upper dead center position and thus causing anincrease in pressure in the passage 32 to cause an increase in velocityof the gases as they issue into the outer space 34. This last-describedarrangement is particularly effective to produce progressive combustionwhere some of the fuel is directed against the mouth of the cavity. Inall the forms the volume of the cavity is preferably less than that ofthe outer space and the dilferential pressure of the gases is utilizedto project the fuel into the outer space.

In each instance it is preferred to form the outer walls of the cavityin the piston by means of a cup 35 which has a flanged portion 36 seatedin a-recess in the piston and a boss at its lower end to receive aclamping screw 37 extending through a centrally located boss in thepiston head and to maintain said cup in a heated condition a clearancewall of said cup and the adjacent wall of the piston head proper.

With the above construction, since that portion of the combustionchamber forming the cavity is only temporarily restricted, the cavitymay be readily scavenged and will be filled with fresh air during eachcompression stroke and injection may be commenced considerably inadvance of upper dead center in high speed engines and only a part ofthe fuel be subjected to the throttling effect during the injectionperiod so that the fuel willloe 27 the cylinder head and 28 the,

efficiently distributed throughout the combustion-supporting air as thepiston starts on its power stroke.

It will be noted that in, each instance the walls of the head curveoutwardly adjacent the projection to reduce the turbulence of the gas orair streams in making the turn from axial to radial so as to decreasethe ener 'y losses and thus allow-the gases to eiiicientdy penetrate theouter space of the combustion chamber.

Ignition may be by heat of compression, by the auxiliary ignitiondevices during starting where heat of compression is insufiicient tostart from cold, or by spark ignition in case of volatile fuels.

it desire it to be understood that this inventoin is not to be limitedto any particular form or arrangement of parts except in so far. as

such limitations are specified .in the claims.v

What I claim as my invention is: 1. In an internal combustion engine,the

combination of a cylinder, a cylinder head toward the walls of thecylinder, and means.

for injecting fuel into said cavity.

2. The method of operating high speed inl jection type internalcombustion engines wherein the piston and head cooperate near the end ofthe compression stroke to form a cavity in restricted connnunieationwith the,

remainder of the combustion chamber which consists in spraying fuel intothe region sur: rounding the mouth of the cavity before the restrictiontakes place and thereafter spraying fuel into the cavity as the pistonnears or starts on its power stroke.

3. In an internal combustion engine, the combination of a cylinder, apiston working therein and a cylinder head, said piston having a cavityformed in its top, said cylinder head having-a projection adapted toenter said cavity near theend of the compression stroke and restrictingthe flow from said space to the remainder of said combustion space, saidpiston and head having walls shaped to provide an annular passage todirect the gases from axial to radial flow, and a restriction beyond theturning point of said gases as the piston nears the end of itscompression stroke.

In testimony whereof, I afli'x my signatur LOUIS O. FRENCH.

